Process for melt spinning and orienting polystyrene filaments



Aug. 18, 1959 1 G. SHAW 2,900,220

PROCESS FOR MELT SPINNING AND ORIENTING POLYSTYRENE. FILAMENTS v 4 Sheets-Sheet 1 Filed Jan. 8. 1954 INVENTOR. GILBERT SHA WY ATTORNEYS. j

Aug. 18, 1959 2,900,220

7 G. SHAW PROCESS FOR MELT SPINNING AND ORIENTING POLYSTYRENE FILAMENTS Filed Jan. 8, 1954 4 Sheets-Sheet 2 INVENTORu G/LBERT SHAW A TTORNE Y5.

Aug. 18, 1959 G. SHAW 2,900,220

PROCESS FOR MELT SPINNING AND ORIENTING POLYSTYRENE FILAMENTS Filed Jan. 8, 1954 4 Sheets-Sheet I5 JNVENTOR. film-5 7- SHAW ATTORNEYS- G. PROCESS FOR MELT SPINNING AND ORIENTING Aug. 18, 1959 -5 w POLYSTYRENE F ILAMENTS Filed Jan.

4 Sheets-Sheet 4 STEAM ,1 4 te l CONDENSATE HZ I?! /90 .w @A H m5 M E B M PROCESS FOR MELT SPINNING AND ORIENTTNG POLYSTYRENE FILANIENTS Gilbert Shaw, Middlebury, Vt. Application January 8, 1954, Serial No. 402,898 Claims. (Cl. 18-54) The present invention relates to a novel process for orientating filaments, and in particular resinous filaments of the type illustrated by polystyrene monofilaments.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the steps pointed out in the appended claims.

The invention consists in the novel steps, combinations and improvements herein shown and described.

An object of my invention is to provide a novel process for orientating filaments in a safe, simple, efiicient and inexpensive manner.

Another object of my invention is to provide a novel process and apparatus for orientating filaments with low breakage of filaments.

The accompanying constituting a part hereof, invention, and together with the description, explain the principles of the invention.

Fig. 1 is a front elevation partly in section away of one embodiment of my invention.

Fig. 2 is a rear sectional view taken along the line 22 of Fig. 3.

Fig. 3 is a side view as taken along the line 3-3 of Fig. 2.

Fig. 4 is a plan section taken along line 4-4 of Fig. 3.

Fig. 5 is a schematic rear view of the heating arrangement of the present invention.

Prior to my invention, resinous monofilaments, as illustrated by polystyrene monofilaments, were oriented or stretched by extrusion into liquid ethylene glycol, glycerinc or concentrated CaCl solution bath at a temperature of approximately 210 to 240 F. From the first bath, the polystyrene was carried into a hotter second bath in the range of 230 to 300 F. where stretching or orientation to the extent of 300-1000% took place. The filament then was passed through water baths to remove the heating solution.

The above described process had many disadvantages. There was a considerable heating solution loss which made the process costly. Also, the equipment presented considerable difficulty when threading the filaments through the hot baths. Breakage in the filaments was high and the hazard of using a hot inflammable solvent, such as ethylene glycol, was not desirable.

In order to overcome the above referred to disadvantages, I have devised my present process and apparatus.

In accordance with my process, the filaments from an extrusion die are brought to their orientation temperature by contacting said filament with a heated moving surface and applying a tensioning force to said filaments while at their orientation temperature. More specifically, the filaments are contacted with and conveyed by at least one and preferably a plurality of heated rollers enclosed in a leak-proof hood member, the natural surface friction of the unoriented filaments preventing slippage at the temperatures involved. After the filaments have been drawings, referred to herein and illustrate one form of the serve to and broken atent mounted on shaft 38a, to rotate.

2,900,220 Patented Aug. 18, 1959 ice 'under tension they are in a straight position while cooling, thus resulting in straight oriented filaments.

Preferably, the means for indirectly adjusting the filaments to the desired orientation temperature comprises a vertical stack of heated rollers enclosed in a leak-proof housing. This housing may preferably be insulated and provided with a chromium plated or aluminum external surface to minimize radiant heat loss. Three sides of the housing are vertically adjustable by means of a counterweight construction with the back portion of said housing being fixedly secured to a supporting frame to insure a leak-proof construction. The drive shafts of each of the motor-driven rolls extend through the fixed back of said shafts having a floating brass sleeve which fits snugly around the shaft to accommodate different positions of the shaft.

In order to describe my invention more specifically, reference is now made to the drawings. Extruded unoriented filaments 1, passing from extrusion die 2, are cooled a suitable orientation temperature as they are conveyed by heated, motor-driven rollers 311 to point A, at which point they are oriented or stretched due to the tensional pull exerted on the filaments. Next, the oriented filaments pass around roller 12 positioned in cooling bath 13 whereby the path of movement is reversed. From roller 12, the filaments pass around roller 14 to roller 15 and back around roller 14 to filament guides 16 and 17 supported by brackets 18 and 19. The tensional pull on the filaments at point A is determined by the surface speed of roller 14.

Heated rollers 3-11 and rollers 15 and 14 are driven by means of a motor 20 in combination with a conventional variable speed pulley arrangement and multiple chain and sprocket drive. The operation of the roller driving means is as follows. Connected to motor shaft 21 of motor 20 is a variabie speed V pulley 22 (Fig. 1) which drives pulley 24 by means of connecting belt 23. Handwheel 25 is provided to adjust the motor supporting plates which in turn adjust the angle of V pulley 22 which controls the speed of the pulley, as is well known to those skilled in the field, such a construction being conventional. Fixedly mounted on shaft 26 of pulley 24 is a sprocket 27 which drives sprocket 29 through chain 28. Mounted on shaft 30 of sprocket 29 is sprocket 31 and roller 15. Thus, on the rotation of shaft 30, roller 15 rotates, as does sprocket 31, which in turn drives sprocket 33 through chain 32.

The rotation of shaft 34 causes roller 14 and sprocket 35, connected thereto, to rotate.

On the rotation of sprocket 35, sprocket 37 is rotated by means of chain 36, which in turn causes sprocket 38, A continuous chain 39 is driven by sprocket 38 which causes sprockets 4047 to rotate. On rotation of sprockets 38 and 40 to 47, rollers 11 to 3, respectively, connected to the shafts 38a, 40a to 47a of sprockets 38 and 40 to 47 will also rotate. The chain 39 on passing around sprockets 38 and 40 to 47 continues its path around idler sprockets 48, 49, 50 and 51 to complete a continuous circuit.

As shown in Figs. 1 to 4, a housing member comprising integrally connected front 52 and sides 53 and 54 and separate back 55 is provided. Front 52 and sides 53 and 54 are vertically adjustable by means of a counterweight 56 enclosed in casing 57, said counterweight belng attached to one end of rope 58 passing over pulleys 59 and 60 with the other end of said rope 58 being con-- nected to a plate 61 having attached thereto two smallv 3 ropes 62 and 63, each having a bracket 64 and 65 attached to its outer end, said brackets 64 and 65 being connected to sides 53 and 54 respectively. Guide rods 66 and 67 passing through guide loops 68 and of supporting brackets 7 Oand 71 are provided, said brackets 70 and 71 being connected to sides 53 and 54 respectively. The upper ends of rods 66 and 67 are fixedly mounted in supporting bearings 72 and 73 respectively, with the lower ends bolted to L-plates 74 and 75' respectively. Rollers 76 and 77 are provided near the lower ends of said rods, said rollers connected to plates 74 and 75 by brackets 78 and 79. v a a As mentioned hereinbefore, the front 52 and sides 53 and 54 of the housing are vertically adjustable due to the above described counterweight construction but the rear 5 is fixedly supported. As best shown in Fig. 4, sides 53 and 54 are provided with inwardly turned lips 80 and 81-, respectively, which are adapted to slide between the spaces provided by vertical strips 82, 83, 84 and 85, respectively. Strips 82, 83, 84 and 85, as well as back 55, are connected to frame member 86 by means of bolts 87, 88 respectively, strips 83 and 85 being spaced from said frame by collars 89 and 90.

Also connected to frame 86 is a vertical plate 91 which hasa plurality of vertical spaced openings in alignment with a plurality of spaced openings in back 55 through which the respective shafts 38a, 40a to 45:; pass. As best shown in Fig. 4, each of the shafts, as illustrated by shaft 42 a, has mounted thereon a floating brass bushing or washer 92 which fits snugly between back 55 and plate 91 to accommodate different positions of the shaft. Each of the shafts passes through a ball bearing unit as illustrated by unit 93 mounted in bearing 94 connected to framemember 95. V a I a Steam passing through rotary steam joints 96 to 104 (Fig. 5) is transmitted to rollers 11-3, respectively, by means of pipes 105-113, as illustrated by pipe 108 (Fig. 4' which telescope in the hollow shafts 38a, 4Qa-47a respectively into their respective hollow a rollers. As shown in Fig. 4, there is sufficient clearance between the pipe 108 and shaft 42a so that condensate outlets back through the shaft and returns to the steam chest 99. Each roller is heated in a manner similar to that shown for roller 8 in Fig. 4. On the return of the steam from the respective rollers to the rotary steam joints it discharged through outlet pipes 114-122 to'steam traps 123-131 and to common outlet tube 132. H

Steam is fed to the pipes 105-113 by passing through common inlet pipe 133 through pipe 134 with portions of said steam being taken off through pipes 113 and 135, said pipes 134, 135 and 113 being respectively provided with valves 136-138, strainers 139-141 and reducing valves discharged from pipe 134 to pipes 105-109; while steam is discharged directly from pipe 135 to pipes 110-112 and directly to pipe 113.

The mode of operation of the above described embodi ment is as follows. The housing is in its down position as shown in Fig. 2 and by manipulating the heating arrangement rollers 3-11 are brought to the desired temperatures, depending upon the type of resin that is to be oriented. Preferably, an increment roller temperature arrangement is used. For example, in orienting a resin filament such as 3 is heated to 2lO-280 F., preferably 210220 F rollers 4-6 from 220300 F. and rollers 7-11 from 240".3l0 F.

After the rollers have been adjusted to the desired temperatures, motor is turned on whereby an insig- F.,. preferably 220-240 240-330 F., preferably nificant first portion of the filaments, which is inferior and unsuitable for orientation, is carried by the rolle'rs3-11, 12, 14 and 15 to guides 16 and 17 Where it is threaded; this threading phase requiring only a few seconds.

after, the orientable and valuable portions of the fila- 142-144. By means of manifold 145, steam ispolystyrene monofilaments, roller There- 1 which time, due to contact with the rollers 3-11, they are adjusted to their orientation temperature. At this point, due to the tensional force on the filaments determined by the surface speed of roller 14, the filaments are stretched. The filaments, while still under tension, are then cooled as they are passed through bath 13 by means of roller 12, after which they pass to roller 14, then to Hand back again around 14, from whence they pass to filament guides 16-17.

It should be realized that the number of rollers used in accordance with my invention will vary depending upon the surface contact that is needed for the particular monofilament that is being oriented. For a needed surface contact the number of rollers that may be used may be accordingly decreased by using rollers of larger diameter to give an equivalent surface contact length, as will be well understood by those skilled in the field. Likewise, the structure of the housing member may be modified andstill be within the spirit of my invention. For example, in place of the housing member as shown in my illustrated embodiment, a housing member may be used wherein only the front fact of the enclosure slides up down with the back panel, sides and top being stationary.

The invention in its broader aspects is not limited to the specific steps, combinations and improvements described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

I claim:

l. A process for the orientation of extruded polystyrene monofilaments and the like, comprising emerging melted unoriented polystyrene monofilaments andthe like from an extrusion die head and bringing said unoriented monofilamen'ts into contact with at least one driven cooling roller heated to a temperature in the range of 2 10' to 330 F. while maintaining monofilament-roller contact for a sufiicient period of time to cool said unoriented monofilaments to orientation temperature in the range of 210 to 330 F., maintaining a sufiiciently insulated zone through which said monofilaments pass while being cooled to and while at orientation temperature to control heat loss from said monofilaments to prevent cooling thereof below orientation temperature, maintaining the monofilaments in an unoriented state while they are being cooled to orientation temperature by maintaining suflicient monofilament-roller frictional contact so that the monofilaments in contact With a cooling roller move at substantially the same surface speed as said cooling roller to prevent monofilament roller slippage prior to orientation, and applying a suflicient orienting tensioning force. to said monofilaments, after they have been cooled to and while at orientation temperature to stretch said monofilaments to a degree sufiicient to produce oriented monofilaments.

2. A process according to claim 1 including cooling the oriented monofilaments While under tension to a temperature below the orientation temperature.

3. A process for the orientation of extruded polystyrene monofilaments and the like, comprising emerging melted unoriented polystyrene monofilaments and the like from an extrusion die head and bringing said unoriented monofilaments into contact with a plurality of driven cooling rollers heated to a temperature in the range of 210 to 330 F. while maintaining monofilament-roller contact fora sufiicient period of time to cool said unoriented monofilaments to orientation temperature in the range of 210 to 330 F., maintaining a sufficiently insulated zone through which said monofilaments pass while being cooled to and while at orientation temperature to control heat loss from said monofilaments to prevent cooling thereof below orientation temperature, maintaining the monofilaments in an unoriented state while they are being cooled to orientation temperature by maintaining suficient monofilament-roller frictional contact so that the monofilaments in contact with each cooling roller move at substantially the same surface speed as the cooling roller to prevent monofilament-roller slippage prior to orientation, and applying a sufficient orienting tensioning force to said monofilaments after they have been cooled to and while at orientation temperature to stretch said monofilaments to a degree sufiicient to produce oriented monofilaments.

4. A process according to claim 3 including cooling the oriented monofilaments while under tension to a temperature below the orientation temperature.

5. A process according to claim 3 including the step of controlling the path of movement of the unoriented monofilaments through the plurality of heated driven cooling rollers in such a manner that opposing sides of said unoriented monofilaments contact adjacent rollers as the monofilaments proceed through the plurality of heated driven cooling rollers.

References Cited in the file of this patent UNITED STATES PATENTS 1,065,235 Goodman June 17, 1913 2,260,501 Wynd Oct. 28, 1941 2,321,635 Taylor June 15, 1943 2,323,383 Dreyfus July 6, 1943 2,581,922 Spencer Jan. 8, 1952 2,631,954 Bright Mar. 17, 1953 FOREIGN PATENTS 924,312 France Aug. 1, 1947 OTHER REFERENCES Ser. No. 715,003, Wultf et a1. (A.P.C.), published Apr. 27, 1943.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.. 2,900,220 August 18, 1959 Gilbert Shaw It is herebfi certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, lines 16, 26, and 29, for "orientating", each occurrence, read orienting same column 1, lines 23 and 24, strike out combinations and improvements"; line 29, strike out "and apparatus"; line 60, for "the above" read these above line 65, for "filament" read filaments column 2, line 24, after "cooled" insert to column 3, line 62, for "increment" read incremented column 4, line 23, for "fact' read face Signed and sealed this 8th day of March 1960,,

SEAL) ttest:

KARL a AXLINE ROBERT C. WATSON Commissioner of Patents Attesting Officer 

1. A PROCESS FOR THE ORIENTATION OF EXTRUDED POLYSTYRENE MONOFILAMENTS AND THE LIKE COMPRISING EMERGING MELTED UNORIENTED POLYSTYRENE MONOFILAMENTS AND THE LIKE FROM AN EXTRUSION DIE HEAD AND BEINGING SAID UNORIENTED MONOFILAMENTS INTO CONTACT WITH AT LEAST ONE DRIVEN COOLING ROLLER HEATED TO A TEMPERATURE IN THE RANGE OF 210 TO 330* F. WHILE MAINTAINING MONOFILAMENT-ROLLER CONTACT FOR A SUFFICIENT PERIOD OF TIME TO COOL SAID UNORIENTED MONOFILAMENTS TO ORIENTATION TEMPERATURE IN THE RANGE OF 210 TO 330* F., MAINTAINING A SUFFICIENTLY INSULATED ZONE THROUGH WHICH SAID MONOFILAMENTS PASS WHILE BEING COOLED TO AND WHILE AT ORIENTATION TEMPERATURE TO CONTROL HEAT LOSS FROM SAID MONOFILAMENTS TO PREVENT COOLING THEREOF BELOW ORIENTATION TEMPERATURE, MAINTAINING THE MONOFILAMENTS IN AN UNORIENTED STATE WHILE THEY ARE BEING COOLED TO ORIENTATION TEMPERATURE BY MAINTAINING SUFFICIENT MONOFILAMENT-ROLLER FRICTIONAL CONTACT SO THAT THE MONOFILAMENTS IN CONTACT WITH A COOLING ROLLER MOVE AT SUBSTANTIALLY THE SAME SURFACE SPEED AS SAID COOLING ROLLER TO PREVENT MONOFILAMENT ROLLER SLIPPAGE PRIOR TO ORIENTATION, AND APPLYING A SUFFICIENT ORIENTATION TENSIONING FORCE TO SAID MONOFILAMENTS, AFTER THEY HAVE BEEN COOLED TO AND WHILE AT ORIENTATION TEMPERATURE TO STRETCH SAID MONOFILAMENTS TO A DEGREE SUFFICIENT TO PRODUCE ORIENTED MONOFILAMENTS. 